Drying system.



W. M. GROSVENOR.

:mum SYSTEM.

APPLIATIN FILED MAB. 1910. 1,1 19,01 1 Patented Dec. 1,1914

3 SHEETS-SHEET 1.

W. M. GROSVENOR. DBYING SYSTEM.

APPLIoA'rIoN FILED MAB. s, 1910. 1,119,01 1. Patented D00. l, 1914.

3 SHEETS-SHEET 2 W. M. GROSVENOR. Damm SYSTEM. APPLIUATION FILED MAR.8. 1910. 1,1 19,01 1 Patented Dec. 1,1914.

3 SHEETS-SHEET 3.

WILLIAM M. GROSVENOR, 0F GRANTWOQD, NEW JERSEY.

DEYING SYSTEM.

Specication of Letters Patent.

Patented Dec. l, 1914.

Application filed March 8, 1910. Serial No. 547,968.

To all whom it: may comer-n:

Be it known that l. WILLIAM M. GnosvEAou, a citizen of the United States, and a resident of lrantwood, Bergen county, and State of New Jersey, have invented ce1'- tain new and useful improvements in Drying Systems, of whichthe following is a lspecification.

My invention relates to improvements in drying systems, various objects of my invention being the simplification of such installations and the increase in their economy, particularly iu such cases as require that the drying be carried out at low temperatures, as in tropical or other locations, where it is desirable to use refrigeration to obtain the required low temperature in the condensing chamber.

A further object of my invention is to utilize the same medium for both heating and cooling drying medium and also to utilize the condensate derived from the drying medium to further cool the refrigerating medium.

Another object of the invention is to provide a system in which the tenipcrature of the drying operation may be increased and the temperature of the condensing operation decreased. or vice versa. by a simple change in a valve` without -the necessity of changing the size or length of the cooling and heating devices or materially altering any of the apparatus and without materially altering the mean temperature of the two or of the systcm.. so that the system may be quickly adj usted to meet the needs of goods of different quality and different kinds of goods.

Further objects, features and advantages will more clearly appear from the detailed description given below, taken in connection with the accompanying drawings which form a part of this specification.

In the drawings, Figure 1 is a vertical transverse section of a system embodying one form of mv improvements, taken along the line I-I of Fig. 2. Fig. 2 is a horizontal section of the same taken on the line H-II of Fig. 1. Fig. 3 is a side view of a modified form of apparatus embodying certain features of my invention. certain parts being broken away in order to more clearly show the same. Fig. el is a plan view of the apparatus shown in Fig. 3.

Referring to Figs. 1 and 2, 1 representsl a suitable chamber or containing apparatus provided with a vertical wall 2 for separating the cooler from thc heatcl partsl of thc apparatus. .it the right of the wall 2 is a series of pipes 3 for heating the drying medium. These pipes are arranged transversely in the lower art of the chamber 1. At the left of the wat?? is a series of pipes 4 for cooling the drying medium. 5 represents a suitable .compressor driven from a pulley 6. The compressor 5 is arranged to compress a suitable refrigerating medium, such as ammonia, into the coils of pipe 3 through the pipe 7. From the coil 3 the refrigeraling medium is led through pipes 8 and 9 to a coil 1() situated within a cooling tank 11. From the coil 10 the refrigerating medium is led through pipe 12 to an expansion valve 13 which may be of any well known construction. From the expansion valve 13 the refrigerating medium is led through the pipe 14 to the cooling coils 4 and from the cooling coils 4 the refrigerating medium is conveyed back to thevcompressor 5 through a pipe 15.

The material to be dried may be supported within the chamber 1 abovethe heating means 3 in any convenient manner, as by trucks, conveyers, racks or other suitable means. Upon operation of the compressor 5 the retrigerating medium is compressed into the coils 3, and due to the action of compression becomes heated and thereby heats the air or other drying medium which circulates thereabout. The drying medium becoming heated rises upwardly about the material to be dried and passes over the topofthe wall 2 whenceit comes in contact with the condensing coils 4, whereby it is cooled and caused to drop, whence it' passes beneath the wall 2 to be coils 3, and so on. In passing through the compartment in which the coils 4 are situated, the drying medium has the moisture `which it has taken up from the material to be dried, condensed, and this condensate is collected by means of a pan 16. The condensate from the pan 16 1s deposited in the tank 11 by means of a pipe 17 Where it acts to cool the refrigerating medium which has been conducted from the coils 3 to the coil 10. From the coil 1() the refrigerating medium is caused to expand into the condensing coil 4, by means of the expansion valve 13 so that the proper temperature is produced to cool the drying mediuln and condense the moisture therefrom.

If it is found that the refrigerating again heated by the heating y medium is not suineiently cooled in the coil l0. an auxiliary coil 18 may be provided within a tank '1U situated below the chamber l mainly to preserve the liquid refrigerating agent in a proper condition on its way to the expansion rali e` l. For this purpose a valve 20 is arranged to close a conduit between the pipes h and Ll and a pipe 2l is connected with pipe 8 which leads to'the coil 1S, wh1le a pipe 22 leads from the coil 18 back to the pipe 9. By closing the valve i2() and opening the valve 23 iu the pipe .21 the refrigerating medium may be caused to pass through the auxiliary coil 18, thereby increasing the amount of cooling given to the refrigerating medium. lhe cooling of the coil 18 may be produced by circulating water or other suitable medium in the tank ll). For thisl pu1 pose a pipe 2l is shown for supplying the tank ll. Suitable overl'low pipes 25 and 26 are provided for the tanks ll and 14 respecti\ ely. It' desired the cooling medium in the tank 11 may also be supplied from some external source.

In case it is found that the compression ol the refrigerating medium in the heating coils 3 does not produce suli'icient heat, as will usually be the case, auxiliary heating coils .T may be piovided just above the same for independently heating the drying medium and these coils may be supplied with steam or other heating means from any suitable external source through the pipe 28 and \alvc 29. In a like manner, i it. is mund that the drying medium is not sufficiently cooled by the coils +1., auxiliary cooling coils 30 may be placed above the coils L and supplied with water or other cooling medium through a pipe 31 and valve llowever lhese coils 30 are provided chiefly to prod nee a relatively warm condensate at the top. which will fall over the main condenser to prevent the collection of frost on the pipes thereof. In various instances it ma y be desirable to use both of the auxiliary coils "3T and 30 in Order to get the proper degree of heating and cooling to get the proper differences and regulation of ternperatures.

In ease it is desirable to allow some of the drying medium to pass outside of the chamber 1 and to introduce fresh drying medium either wholly or partly, the opening is provided in the top of the chamber l with a pivoted door 3l for opening and closing the same. The more the door 311 is opened, the more fresh drying medium is admitted ou the lel't of the same, while the more of the saturated drying medium is excluded at the right of the same. The door 34 may be adjusted if desired so that practically all of the saturated drying medium is excluded, while substantially an entirely fresh drying medium is admitted.

Referring to Figs. 3 and 4, I there show a modification with a suitable compressor 35 for compressing the refrigerating medium into the pipe 36 and coils 37 within the heating chamber 38. From the coils 37 the refrigerating medium is led to the coils 3) by means of a pipe 4:0. The coils 39 are situated within the tank l1 supplied with cooling water through a pipe 42, and provided with an overflow pipe 43. From the coils Clif' the rel'rigerating medium is led to the expansion valve all by means of a pipe 45. From the expansion valve 4l the refrigerating medium is expanded into the coils 46 within a condensing chamber l?. From the coils H16 the rcfrigerating medium is conveyed back to the compressor 35 by means of a pipe 48 in a Imanner similar to that described with respect to Figs. l and r1`he drying medium being heated within the chamber 38, passes upwardly through a duct 179 into the drying chamber 50. The drying chamber 50 is provided with suitable shelves 51 upon which the material to be dried may be placed. After passing about the material in the chamber 50, the drying medium passes through duct 52 along duct 58 and down duct 5l to the condensing chamber 47. The moisture absorbed from the material in the chamber 50 is condensed from the drying medium in the chamber 17 and this condensate is collected in the trap 55 and may be withdrawn through a tap 56. From the condensing chamber 47 and trap 55 the drying medium is led through a duct 57 to a. fan 5S which acts to force the drying medium through the duct 59 up into the heating chamber 38. The'fan 58 thus acts t0 cause forced circulation of the drying medium about a cyclic path so that the same may be used over and over again. If it is desiredto introduce fresh drying medium into the system and exclude the old drying medium or saturated vapors, either wholly or partly, this may be done by pulling down the shutter 60 and closing the shutter 61, more or less, so that the drying medium may pass out into the atmosphere through the duct 62. At the same time the shutter 63 is more or less closed while the shutter 6l is more or less open to admit a corresponding amount of fresh air in through the duct 65.

Connected to the pipe 45 by means of pipes 66 and 67, is a chamber 68. Between the pipes 66 and 67 the pipe 15 is provided with a valve 6l) and the pipe 66 and 67 are provided with valves 70 and 7l respectively. By closing the valves 69 and 71 the refrigerating medium may be compressed into the chamber 68 provided with its own valves and said chamber can then be cut ofi' from the system and removed or may be emptied by the tap 72.

Upon refilling or renewing the chamber 68 with fresh refrigerating medium the same may be forced into the system by open- I pand to ing the valve 71 and then closing the valve and opening the valve 69.

From the above it will be apparent that the operation of both of the systemsshown is similar. The refrigerating medium 1s compressed by the compressor 5 or 35 and the heat due to the compression is utilized in heating the drying medium by means of the coils 3 0137. This somewhat reduces. the temperature of the refrigerating medium and its temperature is then further reduced by the cooling coils 10, 18 or 39. The refrigerating medium is then allowed to exproperly refrigerate the drying medium in the coils 4 or 46 whence it is again conveyed to the compressor and utilized over and over again. Thus by providing the heating means connected with the compression or condensing operation of the refrigerating system and providing the cooling means connected with the expansion or gasifying operation of a refrigerating system, and providing suitable means for securing the proper clrculation of the gases or vapors over the cooling means, the

energy required and the cost of the drying operation is materially reduced and only a single medium may be required for both the heating and cooling of the drying medium. It will also be apparent that the condensed moisture from the extremely cold coils supplied with the refrigerating medium acts through the walls of the tank (#11) to further cool the drying medium and that if desired, the form of said tank may be modified to increase said cooling action when all the cooling action is not required for the refrigerating medium. Furthermore, it will be apparent that this icy condensate from the refrigerating coils can be pumped through the preliminary cooling means as being one source of cold fluid for this purpose or that it may be showered or sprayed through the first part of the condensing chamber in any suitable manner to have a preliminary cooling action on the drying medium before said medium comes in contact with the refrigerating pipes.

Ordinarily if the refrigerating action is sufficient to produce the necessary condensation the compression Will not produce suflicient heating of the medium, and hence in most cases it will be necessary to provide additional heatingr means such as the heating coils 27. in order to make the system balance and dry the goods in a medium of suitable temperature and humidity for the particular goods being dried. In such cases if no auxiliary heating coil were provided, the medium would be so cooled by the condenser that its temperature would not be sufficiently raised by the heater 3, so that the medium would only take up a verv Small amount of moisture from the goods amount of 2T may lnot be needed, but in such case the 1 valve -must' be so will be balanced, a given interval same amount of action of the expansion regulated that the system that is, will condense in of time substantially the moisture as is given off by the goods in the same time. By changing the amount of refrigerating medium in the refrigerating system the mean temperature at which the system operates may be raised or lowered, and by adjusting the size of the expansion opening in the expansion valve the relative difference of temperature ot the medium on leaving the heating coils and on leaving the condenser may be varied. This is especially important, since oods of different quality and different kin s of goods require more or less greater differences of temperature between the medium on leaving the heating coils and the medium on leaving the condenser, and also different mean temperatures. My system is therefore easilv changed to suit these needs, without materially changing the apparatus; or in other words it is not necessary to change the size or length of the heating pipes or increase the cold Water supply to the condenser or the steam supply to the heating coils or the temperature of the two, all of the changes in energy supply being taken care of automatically by the compressor and by merely regulating the expansion valve.

f any excess heat is accumulated in the system owing to the mechanical work being performed on the gases, this may be withdrawn therefrom by means of the cooling coils 18 or 39. By properly setting the expansion valve 13 or 44 the difference in pressure between the heating means and cooling means of the drier may be maintained constant and the di'erence in temperature between the heating chamber and the cooling chamber is thus automatically regulated enabling the operator to closely regulate the humidity in the drying chamber.

A slight increase in the heat left in the drying chamber may be produc'd when desired by the removal of part or all of the cold condensate fiovving through pipe 17 into the tank 11 bv deflecting the same through the pipe 73 and opening valve 74 (see Fig. l). The addition of the coils 27 and 30 also form a convenient means for producing the required .temperatures in the drying mements in great detail, nevertheless I til) dium as well as the required dierences of tem erature therein.

A though I have described my im roveo not desire to be limited thereto except as clearly s ecfed in the a pended claims, since many clianges and m0 iieations may Well be made Without departing from the spirit and scope of my invention.

Having fully and clearly described my improvements, what I claim as new and desire to secure by Letters Patent is 1. In a drying system, containing apparatus constructed to form a closed cyclic path for the drying medium, a portion of said path being formed into a chamber in which the material to be dried or treated may be placed, means for producing-compression and expansion of a refrigeratlng medium, means for heating the drying medium by the compression of the refrigerating medium and causing the drying medium to enter the chamber in a heated condition, and means for cooling the drying medium by the expansion ot' the refrigerating medium to condense moisture from the drying medium.

2. In a drying system, containing apparatus constructed to form a suitable path for the drying medium, a portion of said path being formed into a chamber in which the material to be dried or treated is adapted to be placed, means for producing compression and expansion of a refrigerating medium, means for cooling the drying mcdium after it leares the material to be dried, by the expansion of the refrigerating medium, and means for heating the drying medium before it engages the material to be dried by the compression of the refrigerating medium and causing the drying medium to enter the chamber in a heated condition.

In a dryinc system, containing apparatus constructed to form a suitable path for the drying medium, a portion ot said path being formed into a chamber in which the material to be dried or treated is adapted to be placed, means for producing compression and eX ansion of a refrigerating medium, means or heating the drying medium before it engages the material to be dried bv the compression of the refrigerating medium and causing the drying medium to enter the chamber in a heated condition, and means for cooling the drying medium by the expansion of the refrigerating medium before the drying medium is heated by compression of the refrigerating medium.

4. In a drying system, containing apparatus constructed to form a closed cyclic path for the drying medium, a portion of said path being formed into a chamber in which the material to be dried or treated may be placed, means in said cyclic path for producing compression and expansion of a refrigerating medium, means for heatin the drying medium by the compression o the refrigerating medium and causin the drying medium to enter the chamber 1n a heated condition, and means in said cyclic path for coolin the drying medium by the expansion o the refrigerating medium to condense moisture from the drying medium before it is heated by the refrigerating medium.

In av drying system, a suitable drying chamber for the drying medium means for causing a refrigerating medium to expand independently of the drying medium and means whereby the drying medium is cooled by the retrigerating medium thus expanded, and auxiliary cooling means for independently cooling the drying medium.

6. In a drying system, a suitable drying chamber for the drying medium means for causing a refrigerating medium to expand independently of the drying medium and means whereby the drying medium is cooled by the retrigerating medium thus expanded, and auxiliary cooling means for independently cooling the drying medium, said last mentioned means being arranged so that the heated drying medium will first be cooled thereby and then by the reirigerating medium.

In a drying system a suitable chamber for the drying medium, means for producing compression in a refrigerating medium, means for heating the drying medium by the compressed refrigerating medium before the drying medium enters the chamber, and auxiliary heating means for heating the drying medium independently of the refrigerating medium.

8. In a drying system, suitable apparatus forming a cyclic path for the drying lnedium and a chamber in said path in which material may be dried, a refrigerating system, means whereby the refrigerating system heats the drying medium before it enters the chamber and causing it to enter the chamber in a heated condition, and means whereby the refri gerating system cools the drying medium after it leaves the chamber and before it is heated by the refrigei-ating system.

9. In a drying system, suitable containing apparatus for the drying medium, a refrigerating system with its refrigerating mcdium arranged to heat the drying medium and to cool the drying medium, to condense moisture therefrom, and means whereby the condensate from said cooling of the drying medium Will act t0 cool the refrigerating medium.

l0. In a drying system, containing apparatus forming a suitable path for the drying medium, means for cooling the drying medium to condense moisture' therefrom, a refrigerating system with its refrigerating medium, and means for causing the condensate from the cooling means to cool the refrigerating medium.

11. In a drying system, containing apparatus forming a circuitous path for the drying medium, heating pipes for heating the drying medium, cooling pipes for cooling the drying medium, a compressor for compressing a refrigerating medium into the heating pi es, an expansion valve for causing the re rigerating medium to be expanded into the cooling pipes to condense moisture from the drying medium, means for conducting the refrigerating medium from the cooling pipes to the compressor, means for conducting the refrigerating medium from the heating pipes to the expansion valve, means for causing the condensate from the cooling pipes to cool the refrigeratying medium on its Way from the heating pipes to the expansion valve, means for re lating the amount of cooling of the reii rating medium by said condensate, auxiliary heating means for independently heating the drying medium, and auxiliary cooling means for independently cooling the drying medium.

12. In a drying system, suitable containinv apparatus for the drying medium, a refrigerating system with its refrigerating medium arranged to heat and cool the dry- -ing medium to condense moisture therefrom and means whereby the condensate from said cooling means will act to cool the drying medium.

13. In a drying system containing apparatus forming a suitable path for the dryof two subscribin witnesses,

WILLI M. GROSVENOR. Witnesses:

UroRHAM Cnos, EDWIN Snom.

It is hereby certified that in Letters Patent No. 1,119,011, granted Deoexnber 1, 1914, upon the applieation of `W'illiem M; Grosvenor, of Grantwood, New Jersey, for an improvement in DryingI Systemiff an error appears in the printed speeiti cation requiring correction as follows: Page 5, line 36, strike out the words said cooling means and insert the words the cooling of t/w drying medium by the refrigating medium; and that the said Letters Patent should be read with this correo tion therein that the same may conform to the record of the case in the Patent Oiee.

Signed and sealed this 26th day of January, A. D., 1915.

R. F. WHITEHEAD,

Acting Commissioner of Patents.

[SEAL] 

